This invention relates generally to hand-held dispensers for viscous or liquid products, and more particularly to dispensers of the type wherein a separate container having an upstanding neck part is fitted with a two-piece cap construction comprising a screw cap, and a cap body part, the latter being adapted for securement to the container neck part by means of retention beads, or else by screw threads. In such dispensers, the cap body part and the container normally remain together during shipping and use of the dispenser. The screw cap is usually held captive on the cap body part but is moveable thereon between closed sealing and open unsealing positions.
Dispensers of this general type are well known. Examples of such dispensers are illustrated in the following patents, which are believed to constitute a representative sample of the prior art currently in existence: U.S. Pat. Nos. 3,370,764; 3,598,285; 3,406,880; 3,407,967; 3,216,630; 3,351,249, and 3,319,843, all issued to Morton B. Stull; and U.S. Pat. No. 4,477,002, issued to Gene Stull.
The present invention constitutes another embodiment of the invention set forth in my above-identified copending application.
Dispensers of the type described and illustrated in the above patents were frequently employed with substances such as adhesives or glues of one type or another, which were for the most part, non-volatile. That is, problems caused by some of the material gasifying while still in the container were normally not encountered. Accordingly provision for dealing with build-up of excessive pressures was not made, since there was generally no necessity for doing so, and the chances of such containers bursting or breaking along a seam were minimal.
However, the invention of my copending application above identified was directed to the storage and dispensing of a product capable of gasifying to a limited extent.
In this connection it has been found that with some types of substances, namely certain foods, there can exist a strong tendency for gas to build up within the container after a period of time. The problem is especially troublesome in the category of foods which include mustards. With conventional prepared mustard packaging where an adequate tight seal was employed in order to insure the integrity of the product, there have occurred instances where the container has either burst, or else the caps thereof have been blown off by the internal pressure in the container. In the case of prepared mustard, such an occurrence represents not only a loss of the particular dispenser involved, but in addition, the contents often are splattered with considerable force against adjacent containers, giving rise to the need for removing them from the area where the accident occurred, cleaning them individually, and replacing them. The clean-up represented an unnecessary waste of time as well as being a nuisance, as can be readily appreciated.
Practically all of the present containers of which I am aware do not make provision for the automatic venting of built-up gases therein, since in general the manufacturers and distributors were more concerned with the integrity of the package, that is, making sure that the contents were not contaminated by external means, and also that no leakage of the product occurred during the interim between the filling of the dispenser and the purchase and use by the consumer.